Eugene von Guerard is arguably Australia's most important landscape artist, and when you walk around the latest exhibition at the National Gallery of Australia it is easy to see why.

His work is meticulous, capturing the landscape in extraordinary detail.

This precision helped shape traditional imagery of the Australian landscape, and is referred to by scientists and conservationists researching how the land has changed.

The Nature Revealed exhibition, a travelling show from the National Gallery of Victoria, features many of the artist's iconic paintings of the Australian, New Zealand and European landscapes.

"The precision, the observation of flora and fauna, of topography, of geology is so precise, that the content in many of von Guerard's work has proven to be of immense relevance to us today," said curator Dr Ruth Pullin.

Von Guerard was born in Vienna and trained as a painter in Rome, Naples and Dusseldorf, before migrating to Australia in 1852.

This latest exhibition is the first to offer insight into the artist's early European career.

"He was 41 when he arrived in Australia, and he'd had a significant career prior to that, and so we see his work in Italy, in Dusseldorf," Dr Pullin said.

"We see how not just his paintings but how his engagement with scientific ideas at the time and colleagues really shaped the way he saw the Australian landscape."

Dr Pullin says von Guerard's open air painting in Dusseldorf helped him develop his eye for detail.

"His Dusseldorf studies, oil sketches on paper, reveal a dimension of van Guerard's work we had no idea of before. He was going out to work directly from nature, doing close range, ground-level studies of riverbank vegetation, of running water," she said.

"Developing that eye for detail and precision, and that interest in nature was fundamental to the way he portrayed the Australian landscape."

This eye for detail has lead to his works, like Tower Hill, being used as reference for restoration projects.

"In the mid-1850s ... he recognised the significance of the Tower Hill landscape (in south-west Victoria), so he portrayed it in minute detail," he said.

"As the century went on, this site was gradually destroyed from land clearing, grazing, fire, mining. By the end of the century it was basically a wasteland.

"In the mid-20th century there was a move to restore Tower Hill to its original state. Botanists at the time could recognise 13 of the plants on the basis of von Guerard's portrayal.

"And so this painting became basically, a template for the revegetation of Tower Hill."

Von Guerard also painted the Neander Valley near Dusseldorf, before the bones of the Neandathol man were discovered there in 1856.

"The artist had no idea that this was going to be the site where Neandathol man's existence would be discovered. They went into the Neander Valley to portray the unique species, the ancient plant species that sheltered in this rocky gorge," she said.

"In 1856, mining in the area began for a railway that was put in the area, and that site too was destroyed.

"So van Guerard's paintings of the Neander - just like his work of Tower Hill - is a very precious record of the rare and ancient plants that lived in the Neander Valley."

Yet this meticulous detail was criticised by some in the art circle during the 1870s.

"Von Guerard wrote an emotional letter defending his art. He said he felt his work would be of much greater value in the future, because it was so geologically and botanically precise," Dr Pullin said.

"He said it would be more valuable than all those misty scenes that could just as well be England or anywhere else."

Some of von Guerard's sketchbooks and lithographs are also on show for the first time.

"Drawing was absolutely essential to his work. He carried little pocket sized sketchbooks with him wherever he went. They were so detailed and had little notations in old German," Dr Pullin said.

"He would produce a work in a studio, perhaps spending two or three months on each painting. And underneath the work there would be meticulous underdrawing. We know using infra-red technology, we can see the underdrawing very very precisely."

Eugene von Guerard: Nature Revealed is on show at the National Gallery of Australia until July 15.